Flooding has crippled Orange County, N.Y., and will likely have a significant economic impact on large swaths of the area’s agricultural land, a local official said Monday.

Since Tropical Storm Irene landed, several large bodies of water of overflowed into major roadways, highways and the streets of more than 70 smaller towns and cities, said Richard Mayfield, the director of operations the county.

Mayfield said the deluge had destroyed bridges and is threatening to ruin lettuce, celery and onion crops. Relief from the flooding is not yet in sight: The Wallkill River, which he described as a “slow moving, sluggish” river, has not crested, adding uncertainty to an already exasperated region. Of the major thoroughfares that traverse the county, only Interstate 84 remains passable.

“It’s not over for us,” Mayfield said. “It’s a significant hit to our county infrastructure.” The economic impact of the flooding remains unclear but will likely pose a “tremendous burden,” he said.

So far, nearly 800 people have evacuated flooded areas into Red Cross shelters and local shelters run by individual towns, cities, churches and senior centers. Mayfield said some will not be able to return home to houses that will be deemed structurally compromised.

Orange County is home to several major rivers, including the Hudson, Wallkill, Ramapo, Delaware and Neversink, as well as a number of smaller creeks, lakes and ponds. The water is also straining and threatening old dams.

There have been no fatalities or serious injuries attributed to the storm in Orange County, Mayfield said